1. Field of the Invention
This invention relates to polymeric materials which will reversibly dissociate into the starting materials from which they were prepared or into liquid oligomers at temperatures in the range of from 100.degree. to 150.degree. C.
2. Description of the Prior Art
In the past, plastic bonded explosives have typically utilized crosslinked thermosetting polymers as binders. These binder materials have both desirable and undesirable characteristics.
One desirable characteristic is the fact that their use permits one to make choices which permit the control of physical properties of the explosive. Another is that explosives utilizing them tend to be highly shock resistant. Still another is that explosives utilizing them tend to have high impact strength. Further, explosives utilizing them are useable above the usual upper service temperature limit of melt-cast explosives. Still further, explosives utilizing them can even be used as structural components.
Among the disadvantages of using such binders is the fact that the binder has a limited pot-life during which it has manageable viscosity and pour characteristics. Another disadvantage is that compositions containing them cannot be recycled once the binders have cured completely or even partially if the binder viscosity does not permit void free casting. Also, explosives utilizing them are extremely difficult to remove from outmoded ordnance or the like.
With the foregoing disadvantages in mind, it was sought to develop polymeric binders which would reversibly dissociate into the starting materials from which they were prepared or into liquid low molecular weight oligomers upon exposure to elevated temperatures. Reversibly dissociable binders offered the potential advantages of (1) extended (ideally infinite) pot-lives during mixing and formulation; (2) reduced waste since scrap or recovered explosive could be recycled back to the mixing kettle; (3) desensitized explosive compositions because heat would be removed from "hot spots" by endothermic dissociation; (4) possible use of dense, energetic co-monomers as curing agents; and (5) easy removal of explosive compositions containing them from outmoded ordnance and the like.